DE69826675T2 - IMPLANTABLE DEVICE WITH IMPROVED ARRANGEMENT FOR BATTERY CHARGING AND ENERGY SUPPLY - Google Patents

Abstract

An implantable system, such as a neural stimulator or a cochlear implant system, includes a rechargeable battery configuration having improved recharging and lifetime characteristics. The battery is housed within the implant's case and has first and second electrode plates. Each electrode plate has a plurality of slits that extend across a substantial portion of the plate's surface area. The slits in the electrode plates reduce the magnitude of eddy currents induced in the plates by external ac magnetic fields allowing faster battery recharging times. Alternatively, the electrode plates are wrapped in a spiral configuration such that, in the plane of the spiral, the electrode plates have a small cross-sectional area and no closed current loops. Additionally, the implant device may be housed in a case formed of a high-resistivity material and a circuit included in the implant device is configured to avoid large current loops that would result in eddy current heating. As a backup option, the circuitry of the implant device may optionally be powered from an external battery that inductively couples energy to the same coil that is used to charge the internal battery. In one embodiment, the implantable system is partitioned into first and second implantable cases, each having electrical circuitry therein, and only one having a rechargeable power source therein, facilitating its subsequent replacement for repair or upgrading purposes. The two cases are coupled together when the system is in use. Coupling is achieved either magnetically and/or with a detachable electrical cable. In one embodiment, power is transferred from one implant case to the other using a 3-phase transmission scheme.

Description

BACKGROUND THE INVENTION

The The present invention relates to implantable devices, and especially a complete one implantable device or system for stimulation or sensing ("sensing") of living tissue, in which the implantable device is a rechargeable battery or another refillable or regenerable energy source has. An aspect of the invention relates to an implantable device designed to minimize the heat generation due to eddy currents when charging the battery and other magnetic drives formed is. Another aspect of the invention relates to partitioning the circuit functions in the implantable system, so the arming to enable the circuit functions and / or existing, partially implantable systems (which includes both implanted and external, or non-implanted, Has components) into a fully implantable system to convert. EP-A-499 939 discloses in combination the technical Features listed in the preamble of claim 1.

Currently available implantable stimulation devices, such as B. a cochlear Implant device or a neural stimulator, usually own an implanted unit, an external AC coil and an external, on a strap attached control unit and a power source. The external control unit and the power source include a suitable control processor and other circuits that receive the appropriate command and power signals and send them to the implanted unit, causing them is able to perform the function assigned to it. The external control unit and the power source are connected via a Battery powered, the electrical power through the AC coil the implanted unit over supplying an inductive coupling, giving power for a necessary signal processing and the control circuits provided and electrically stimulates selected nerves or muscles become. An efficient transmission of energy through the skin of a Patients from the external unit to the implanted unit via the Inductive coupling requires a constant tight alignment of both Units.

rechargeable implantable tactile and / or pacing devices (eg, cardiac pacemakers) relatively large Devices with dimensions of z. B. 75 × 50 × 12 mm (3 × 2 × 0.5 inch), and are relative heavy. Further need these rechargeable implantable devices a relative for a long time each week to recharge. Other significant revelations include: US-A-5314457, US-A-541153; US-A-4006748; US-A-4134408 and US-A-4041955.

Corresponding is there a need for a small, lightweight implantable device that is not a constant external power needed and which includes a permanent internal battery, which within a very short period of time can be recharged.

Should the battery within such a small, lightweight implantable Device does not work, or should the operator the internal battery for do not want to use certain periods of time, there is also a Need for the device continues to supply power, for. B. from an external Power source, so that the device continue its operation and can provide the function assigned to it to the patient, z. As the scanning and / or stimulation, without a new device must be implanted in the patient. There is also a need for a fast, easy process, the battery module during the Exchange operation, the exchange should be necessary or desirable.

moreover there are many patients who have received an implant system such as B. a cochlear implant system of the kind as in US Pat. No. 5,693,726 which has both an implantable cochlear stimulator (ICS) attached to an inserted into the Kochlear electrode assembly attached, as well as an external (non-implanted) battery, a language processor and a header. The language processor (SP) and the battery are housed in a portable unit, which is worn or held by the patient, e.g. B. at one Fanny pack. The head part includes the external AC coil, a magnet and a Microphone. It is connected to the portable unit via a cable. at In use, the headboard is located near the outer skin the patient, in the immediate vicinity of the ICS, so as to provide an efficient inductive coupling herewith. Of the Magnet is positioned and holds in a proper way the head part at the ICS implant site. Many of the patients who Owning and using the existing ICS system could be done in great Measures of one completely implantable system have advantages such. As a system, at no external components of the system are carried and / or held Need to become. The present invention addresses this as well as other needs at.

SUMMARY THE INVENTION

The The present invention is defined in claim 1 and in a rechargeable one Implemented device for implantation in living tissue, which improved Battery charging and Lifespan properties possesses. In some embodiments the rechargeable device of the invention can be used to the ICS section from existing implant systems to complete implantable Upgrade systems. In other embodiments if the device is designed to minimize unwanted eddy currents, the heat when charging the battery. Accordingly, the device be charged relatively quickly, causing interruptions in relation on the lifestyle of a patient can be minimized. Im charged or charged State, the device can be used to various types Drive implant configurations, including a fully implantable one single unit ("single unit "), a wired one System ("wired system") or a nutritional system ("proximity system").

In addition, can the rechargeable device through a small, lightweight external Unit, if necessary or desired, driven continuously be used as a backup option or for diagnostic purposes. On this way it is in the case where the internal (implanted) Battery inside the device does not work, or off any other reason can not be used, or the Operator or hospital doctor (or other medical Staff) they do not want to use, still possible, one Operating power for the implantable device through the use of lightweight provide external device so that they have their assigned function continue to provide (eg, pacing and / or palpation). By having such a backup option available, the patient can advantageously, indefinitely the replacement of the battery and / or delay a corrective operation.

A Device, hereinafter referred to as the "single unit" or "single unit" device is realized as an implantable device, the one Casing, a coil, electronic circuits and a rechargeable battery has. The housing forms a substantially hermetic dwelling and the coil surrounds the case, a relatively large one Enclose area, and generates electrical power in the presence of externally induced alternating magnetic fields, which by the enclosed by the coil Range run. The rechargeable battery and the electronic Circuits are housed in the housing. The battery includes a first and a second electrode for storing the electrical Performance of the coil and providing electrical power to the device. Each of the two electrodes has a relatively large surface area for the Storing the electrical power that is designed to prevent such current paths, which are able to relatively size To form current loops. The suppression of such current paths restricts heat generating eddy currents in the Electrode resulting from the magnetic fields, which pass through the area enclosed by the coil, and the go through the battery as well.

A another device, hereinafter referred to as the "wired system", is considered a complete one implantable system realizes the two implantable devices includes their own housing own and over a detachable cable are connected together. The first of the implantable devices contains electronic circuits to run a desired one Function. The second of the implantable devices includes a rechargeable battery or other regenerable or rechargeable power source, and can be just as extra Circuits include. The second device provides an operating performance for the first implantable device ready. The detachable cable, the The two devices can connect to each other at each end comprise a transformer coupling. A suitable switching circuit is with the battery in the second device includes the DC power of the battery in an AC power for transmission to the first device to convert. This AC power can be modulated as desired, as well as information, e.g. As control signals, from the second device to transmit to the first device. In this way runs only AC power through the connection cable.

Another device, hereinafter referred to as the "proximity system" device, is realized as a fully implantable system comprising a first and a second implantable device. The first device includes an electronic circuit for performing a desired function. The second device includes a rechargeable battery or other regenerable power source and may also include additional circuitry. There is no direct electrical or physical connection between the two devices through which power and / or control signals are communicated from one device to another. There is no detachable Cable connecting the two devices together, as in the case of the "wired system" device Power and control signals are transmitted rather inductively (magnetically) from the second device to the first device (in the same way as in the case) wherein power and control signals are coupled between an external unit and an implanted unit in existing systems.) Use of this nursing system device allows for the implantation of a second device housing a rechargeable battery or circuits previously contained in an external device adjacent to an implant device of an existing system, thereby effectively upgrading the existing system to a fully implantable system.

A Variation used with any of the above devices is in an implantable device in which the housing is formed of a material having a relatively high resistance, the to similar ones Way heat-producing eddy currents in the case limited.

A further variation, with one of the preceding devices can be used, includes a circuit that is also in the housing is included, and which is designed without relatively large current loops be formed to heat-producing eddy currents in the circuit limit.

According to the invention, a rechargeable battery used externally induced magnetic alternating fields is exposed, and one in the essential hermetic dwelling and first and second electrodes included in the hermetic dwelling for storage and providing electrical power. Each of the electrodes is designed to prevent the formation of relatively large current loops. In particular, each electrode may have a relatively flat conductive plate which is essentially in one plane, and the slots in the flat plate, so the area of endless loops to reduce in the plane of the plate. The two electrodes can as well conductive bands which are wound into a spiral without being a closed one Loop is formed along the spiral. Alternatively, the first electrode of four bands be formed, which are connected in parallel, and the second electrode can be made up of four bands be formed, which are connected in parallel. The four bands of the first electrode and the four bands the second electrode are formed into a wound spiral, without making a closed loop along the spiral becomes. The hermetic dwelling can also be made of a material with high resistance to heat generating eddy currents in the Limit housing.

The The invention may be realized as an implant device, such as z. A cochlear stimulation device or a neural stimulator device, the a relatively flat housing, a housed in the housing electronic circuit, a coil surrounding the housing and a also in the case has housed battery. The electronic circuit generates electrical pulses to stimulate, e.g. As the Kochlear or other Nerves, and the coil is essentially parallel in one plane to the flat section of the housing and receives electrical power coming from external AC magnetic fields is induced. The battery is charged with the coil for charging Battery coupled and has a first and a second electrode plate. Each electrode plate has a surface area that is relatively parallel to the plane of the flat housing and which is designed to reduce the amount of eddy currents, those in the plate through the external AC magnetic fields be induced when charging the battery in the plate.

at a special embodiment of the invention are the surface areas the two electrode plates are relatively flat and have a length of approximately 25 mm (1 inch) and a width of about 25 mm (1 inch). Each electrode plate has a variety of slots that span a substantial section of the surface area of the plate so as to produce regions of the surface area of each one has a relatively long, slender shape. All Slots are essentially parallel and form a crest conductive Teeth. The conductive Own teeth a width of about 1 mm (0.04 inch), and the slots have a width of about 0.25 mm (0.001 inch) and one length of about 23 mm (0.9 inch). The slots form gaps between the conductive teeth, the can be filled with an insulating material, such as. Nylon, polypropylene, Epoxy or other compatible insulating materials.

In another embodiment of the invention, the housing is formed of a metal having a relatively high resistance, such as. For example, the alloy may be titanium ₆₄ (6% aluminum, 4% vanadium), or titanium ₈₁₁ (8% aluminum, 1% molybdenum, 1% vanadium), and it may be coated with an epoxy or plastic. The cochlear implant device may further comprise a coil forming the housing surrounds and embedded in the epoxy for receiving externally induced AC power. The battery may be a lithium ion rechargeable battery, and the device may further include a recharging control circuit connected between the reel and the battery for recharging the battery to a specific voltage, such as a rechargeable battery. 4 volts, or a specific Coulomb amount of electrical current using the power induced or received by the coil. Alternatively, the apparatus may further comprise a Coulomb counter which measures the charge delivered to the battery during charging and the charge discharged by the battery during discharge.

In a still further embodiment According to the present invention, the device is an implant device, the one housing, a battery and an implant lead extending from the housing includes. The lead has a plurality of electrodes for stimulation cochlear nerves within the cochlear, or to stimulate others Body Parts. The battery is in the case housed and has first and second electrode plates. each Electrode plate has a surface area with a plurality from slits that are over extend a substantial portion of the surface area of the plate, so as to create areas that have a relatively long, slender shape have. Compared to a plate without slots with a similar one surface area reduce the slotted electrode plates of the present invention the extent of through the external AC magnetic fields in the plate induced eddy currents. The reduced eddy currents enable larger magnetic Fields with less warming to to allow a faster charging of the battery.

The The present description discloses a method for charging a Battery in an implant device, eg. B. in a cochlear Implant device that induces an alternating current in a coil that surrounds the implant device or which is included in the implant device or with the help of two or more wires is attached to the implant device and the rectifying the induced alternating current to produce a direct current, and charging the battery using direct current, and although until the battery voltage reaches a predetermined battery charging voltage or reaches a predetermined coulomb value. For the maximum Battery life of a lithium-ion battery becomes the battery is charged to a voltage of not more than about 4 volts and is to a voltage of not less than about 3 volts discharged.

One such recharging method may also be used be a backup operating power for the implant circuit in the case where the internal rechargeable Battery does not work or should not be used. A such backup power delivery can z. B. be achieved by the same or a similar small lightweight external device is used for charging the battery is used. With the option of providing a Backup performance is advantageously enabled for the patient a corrective and / or battery replacement purpose Postpone the operation indefinitely.

The Backup power delivery option allows greater flexibility, how the implant stimulation device is used. For example, can in the cochlear implant device it would be advantageous to use the Change language editing strategy, which is used to stimulate the auditory nerves in to control the Kochlear. Such a language editing strategy is programmed primarily in the implantable device. Should a new language editing strategy be desired, so also in the case in the reprogramming of the language editing strategy within the implantable device is not feasible or possible, so could a small, lightweight unit worn behind the patient's ear that incorporates the new language editing strategy and the implanted stimulation circuit in the implantable Device drives and controls, so as the new stimulation strategy apply.

The Invention includes an implant system consisting of two packages consists. In a specific embodiment, the first one comprises Pack the coil, battery, battery charging and power regulating circuit and some of the electronic circuits (the signal transfer and the processing circuitry) that may be updated or upgraded in the future Need to become, when new signal processing and data processing technologies arise. The second pack encloses the wires leading to the stimulation and touch electrodes and the devices as well as the interface circuits stimulation and sampling and the other signal processing and conditioning circuits that closely match those in the second pack executed Stimulation and tactile functions are linked and possibly not changed or updated or upgraded Need to become, when new technologies emerge.

In this way, the first pack is a pack that, if needed, at a future time can be replaced or updated by a small replacement operation. The second pack is a pack that would never need to be replaced or upgraded once implanted.

In Both packages contain circuits that are capacitive coupled data transmission enable, and there are receive circuits that are used to to transfer data and power between the two packs. The packs can with a detachable cable ("wired System ") be or can over each other an induction coupling ("nutritional system") be coupled. In the wired system can exemplary data between the two packs with the help of two or transfer three wires be while Performance on three wires over one capacitively coupled three-phase square wave signal can be transmitted, the prevents DC outside of the hermetic seals of the packages flows. The three-phase signal can simply being recombined on receipt at the other pack, to a DC signal using a synchronized Circuit with negligible To produce ripples without using filter capacitors have to. In the nutrition system will power over transmit an AC carrier signal, and data is transmitted by modulating the carrier signal.

SHORT DESCRIPTION THE DRAWINGS

The The foregoing and other aspects, features, and advantages of the present invention The invention will be described in more detail below with reference to the following Description taken in conjunction with the accompanying drawings:

1A FIG. 10 illustrates a typical cochlear pacing system as currently used by many patients, including an implantable cochlear stimulator (ICS) inductively coupled to an external header (HP) connected to an external speech processor (SP) and a power source ,

1B FIG. 10 illustrates a cochlear pacing system for the back of the ear (BTE) that includes an implantable cochlear stimulator (ICS) and an external BTE unit that includes a power source, a speech processor, and a microphone.

1C Figure 1 shows a type of single unit of a fully implantable system made in accordance with the present invention.

1D Figure 1 shows one type of fully implantable, partitioned wired system according to the invention.

1E Figure 1 shows one type of fully implantable, partitioned nutritional system according to the invention.

2A Figure 11 is a plan view of a representative unit of a fully implantable cochlear implant device according to the present invention.

2 B FIG. 10 is a plan view of an AC power take-off coil for use in recharging a cochlear implant device battery. FIG 2A ,

3A . 3B and 3C FIG. 12 are plan views of exemplary battery electrode plates for reducing induced eddy currents on the plates according to the present invention.

3D represents a way according to which in the 3B and 3C shown electrode plates can be rolled to form a small battery.

4 is a side view of a battery electrode plate and a separation stack.

5 is a cross-sectional view taken along the line 5-5 of 1 showing an epoxy coating covering the cochlear implant device.

6 FIG. 12 is a plan view of a circuit board having predetermined circuit areas for reducing the AC currents according to the present invention. FIG.

7 FIG. 10 is a plan view of a first embodiment of a helical battery electrode configuration according to the present invention for reducing induced eddy currents. FIG.

8th is a side view of the battery electrode of 7 before the electrode was rolled into the helical configuration.

9 FIG. 12 is a plan view of a second embodiment of a helical battery electrode configuration according to the present invention for reducing induced eddy currents. FIG.

10 is a side view of an electrode attachment ring for parallel electrode connection of the spiral battery of 9 ,

11 is a representation of the battery voltage versus the battery capacity.

12 Fig. 12 is a side view of an elastic circuit board before being rolled into a C-shaped or spiral configuration.

13 FIG. 12 is a plan view of the elastic circuit board of FIG 12 which has rolled into a C-shaped or spiral configuration.

14A and 14B Figure 10 is a plan view and side elevation, respectively, of one embodiment of a fully implantable, partitioned nutritional system according to the invention.

15A and 15B Figure 10 is a similar plan view and side elevation, respectively, of another embodiment of a fully implantable, partitioned nutritional system.

16 Figure 11 is a side elevational view of another embodiment of the partitioned nutrition system.

17 FIG. 12 illustrates a functional block diagram of the circuitry used in a partitioned nutrition system of the invention. FIG.

18 Similarly, FIG. 12 illustrates a functional block diagram of the circuitry used in one embodiment of the partitioned wired system of the invention.

19 Figure 12 shows a block diagram of a preferred three-phase transmission system for transmitting power between two implantable devices.

20 is a waveform diagram illustrating the operation of the three-phase transmission system of the 19 represents.

Appropriate Reference numerals indicate corresponding components in all Views of the drawings.

DESCRIPTION THE PREFERRED EMBODIMENTS

The The following description is that of the "best mode" currently used to execute the Invention is considered. This description should not in the sense of a restriction be understood, but merely for the purpose of description made of the general principles of the invention. The area The invention should be determined with reference to the claims.

Overview

The present invention relates to a fully implantable device having a rechargeable battery (or other power source). In a preferred embodiment, the implantable device has a fully implantable cochlear pacing system and, therefore, such a cochlear pacing system is described herein. It will be appreciated, however, that the present invention may be used with other types of implantable systems as well, and is not limited to only a cochlear pacing system. Any medical or other device or system that needs to be implanted in living tissue, or in a similar environment, and that requires operating power from a regenerable or refillable power source, such as z. As a rechargeable battery, and must be inductively or magnetically or otherwise coupled into the implantable device in the operating performance, without a direct electrical connection, can benefit from the application and teaching of the present invention.

To better understand and appreciate the present invention, it will be helpful to briefly review current or existing cochlear stimulation systems that are representative of all tissue stimulating systems. A representative cochlear stimulation system of the variety currently used by many patients is fully e.g. In US Pat. No. 5,603,726, previously incorporated by reference. As described in the '726 patent and in the 1A As shown, such an existing system includes implanted and external components. The external components include a speech processor (SP), a power source (eg, a replaceable battery), and a header (HP) 106 , The SP and the power source are typically in a portable unit 102 housed, which is worn or held by the patient. The portable unit is with the HP 106 over a cable 104 electrically connected. A microphone 107 is also part of the header 106 contain.

The implanted components include an implantable cochlear stimulator (ICS) 112 and an electrode assembly 114 , The electrode arrangement 114 is implanted into the cochlear space of the patient. The ICS 112 is implanted behind the ear so that it is near the scalp.

The electrode arrangement 114 is with the ICS via an implantable multi-conductor cable 116 permanently connected.

Inside the headboard 106 There is a coil that is used to inductively or magnetically couple a modulated AC carrier signal into a similar coil that is in the ICS 112 is included. In order to achieve efficient coupling without incurring significant losses in signal energy, it is important that the external coil in the header be properly aligned with the internal coil in the ICS. To achieve this correct alignment, a magnet is usually in both the header 106 as well as the ICS 112 and the resulting magnetic attraction between the two magnets not only aligns the coils but also provides a holding force to the head portion 106 in a safe way against the scalp or the skin 110 of the patient.

In use, a carrier signal from the circuit in the portable unit 102 using the power coming from the power source in the voice processor unit 102 is won. Such a carrier signal, which is an AC signal, becomes the header via the cable 106 Transfer where it is with the coil in the ICS 112 is inductively coupled. There it is rectified and filtered and sees a DC power source for the operation of the circuits in the ICS 112 in front. Noises are caused by the external microphone 107 perceived, amplified and by those in the voice processor unit 102 contained circuits and processed to appropriate stimulation signals according to a selected language processing strategy by circuits in the speech processing unit 102 converted. These stimulation signals modulate the carrier signal, the power to the ICS 112 transfers. The ICS includes a suitable demodulation circuit that retrieves the stimulation signals from the modulated carrier and applies them to the electrodes in the electrode assembly 114 applies. The stimulation signals indicate which electrodes, or electrode pairs, should be stimulated, including the intensity of the stimulation.

Some embodiments of the ICS 112 As indicated in the '726 patent, a telemetering feature ("backtelemetry") involves transmitting the data signals from the ICS 112 to the headboard 106 , and therefore to the speech processor 102 allows. Such telemetry data provides important feedback information to the speech processor regarding the operation of the ICS.

If adjustment or regression or other diagnostic procedures are required, an external programming unit is required 108 removable with the SP unit 102 connected. By using the external programmer 108 For example, a clinician or other healthcare professional may select the most favorable language editing strategy for the patient as well as other variables associated with the stimulation process. Reference is made to US Patent No. 5,626,629 for a detailed description of a representative regression / diagnostic process.

Although that in 1A As has been shown for many patients of great value and utility who otherwise had no hearing, there are some disadvantages associated with using the system. For example, the portable unit needs 102 be worn or held by the patient, and the Ka bel 104 , which can be up to a meter long, must be from the unit 102 to the headboard 106 run. Some of the patients found wearing the unit 102 as annoying and the use of the head part 106 with his cable 104 as unsightly and not comfortable.

To go without the cable 104 Being able to get along can be a behind-the-ear (BTE) unit 120 used as they are in 1B is shown. The BTE unit 120 includes everything that was previously in the wearable 102 contained, but in a much smaller volume. The BTE unit 120 thus includes a suitable power source as well as circuitry for performing a desired speech processing function. With the BTE unit 120 does not need a cable 104 and the patient simply carries the BTE unit behind the ear, where it is barely noticeable, especially if the patient covers the BTE unit with his hair.

The batteries in the portable unit 102 ( 1A ) or the BTE unit 120 ( 1B ) can be advantageously easily replaced, if necessary. The BTE unit 120 may be unpleasant to wear for extended periods of time, and may need to be removed at certain times, e.g. B. when swimming or swimming. However, some of the patients would prefer to be able to hear at all times, including swimming or bathing, and thus a fully implantable stimulation system is desired.

The The present invention relates to fully implantable devices and systems where a rechargeable battery or other Regenerative power sources are used. While out In the prior art, the use of an implantable stimulation device with a rechargeable battery is known, see, for. B. the earlier US Pat. No. 3,942,535 of the applicant Schulman, such require Charging systems a great external charging system, and are time consuming to use. In contrast to this end, the present invention provides a rechargeable battery and a method for recharging the battery, which is a fast and convenient recharge, without significantly affecting the patient's lifestyle.

The present invention also enables different implant configurations to be used as part of the fully implantable system, including the possibility of the ICS 112 conventional systems in a fully implantable system.

A fully implantable system 130 with only a single unit according to the invention is in 1C shown. As in 1C includes such a system 130 the ICS circuit, the speech processing circuit and a power source in a single unit 132 , An electrode arrangement 115 is with the single unit 132 connected in a conventional manner. At the in 1C embodiment shown is a microphone 134 via a telecoil connection with the single unit 132 coupled. Such a telecoil connection supplies the microphone circuits from the unit via a magnetic coupling 132 with energy. The one from the microphone 134 recorded sounds are sent to the unit 132 via an RF transmitter in the microphone 134 is installed, transferred. (The transmission section for such a signal is very short, only 1 or 2 cm, so that not much power is needed for the transmission). Advantageously, such a microphone 134 introduced into the auditory canal so that it is not visible from the outside.

Different microphones can also work with the implant unit 132 be used. For example, externally generated sound waves can pass through the patient's skin and through the housing of the individual unit 132 be detected at locations where the housing core is very well formed and has the appropriate thickness.

If in the single unit 132 If there is a need to recharge your battery, which can only be a few minutes a day or a few times a week, you will have an external headboard 136 adjacent to the unit 132 and inductive coupling is used to transfer the charge power to the battery of the unit. The external header is again with an external control unit 138 which in turn receives its power from replaceable batteries or from an AC power plug. If programming and / or diagnostic tests are needed, an external programmer can 108 in a detachable way with the external control unit 138 get connected.

The external control unit 138 Used to charge the battery inside the implanted unit 132 to load / recharge, as well as for other purposes. For example, the external control unit 138 used to replace the internal speech processor with an external speech processor, e.g. B. a speech processor running in the external programmer 108 is included. The external control unit 138 can also be used to increase the power provided by the internal battery. The external control unit 138 can also be used to the implant device 132 to program, z. B. Adjusting the ICS after Implantation or Adjusting the Stimulation Parameters of the Fully Implantable Unit 132 , as well as for diagnostic purposes.

At the in 1C shown embodiment 130 as well as in the in the 1D and 1E In the illustrated embodiments described below, it will be appreciated that telemetry may be employed to transmit data signals from the implanted unit to the external header 136 , and therefore to the external control unit 138 to enable.

Referring now to the 1D is a "wired system" embodiment 150 represented the invention. In such a wired system 150 Be at least two separate implantable units 152 and 154 and the circuits of the system are partitioned between the two units. In a first unit 152 are z. For example, the speech processor (SP) and the ICS circuit are housed, and such a unit is permanent with an electrode assembly 114 connected. In a second unit 154 are housed a battery, or other suitable power source. The second unit 154 is with the first unit 152 via a detachable cable 156 electrically connected. In a preferred embodiment, only the power unit is 154 with the SP / ICS unit 152 coupled across AC power so as to prevent a DC current from flowing through the tissue through which the cable is routed. This is important because direct current could damage the tissue, while this is not the case with alternating current. Because the cable is not hermetically isolated from the surrounding tissue, it is very possible that a small leakage current can flow through the tissue if DC currents flow in the cable.

The second unit 154 includes a suitable switching circuit which converts the battery-related DC power (or other power storage element) into an AC signal for coupling to the first unit 152 converted. Likewise, an appropriate circuit is used to operate in the unit 152 induced AC power from the external header 136 to the battery of the unit 154 to transfer so as to charge the battery.

Even though the preferred power source for use within the fully implantable system, which is described herein is a rechargeable battery, however, it can be seen that other sources of power are used as well can be. For example, an ultra-capacitor (also known as super-capacitor) be used. An ultra-capacitor, similar to a conventional one Capacitor allows the storage of electrical charge (voltage potential). unequal a regular one Capacitor is the energy density of the ultra-capacitor by orders of magnitude greater than the energy density of a normal capacitor, thereby allowing that a big one Amount of energy can be stored in the ultra-capacitor. These stored energy can then be dissipated by the ultra-capacitor for the subsequent Use be deducted. For this type of application where recharging takes place at regular intervals and if appropriate discharge circuits are used To control the discharge rate or the energy deduction, so the sees Ultra-capacitor is a viable alternative to a rechargeable Battery for use within the implantable system.

A suitable microphone, z. B. a "complete-in-cannel" (CIC) microphone 134 of the kind previously described is used to detect noises and couple those signals representative of such sounds to the speech processor (SP) circuits in the respective implantable section.

It should be noted that the partitioning in 1D and showing the ICS and SP circuit in the first implantable unit 152 is included, and which also shows that the power source, e.g. As a rechargeable battery, in the second implantable unit 154 is included, such partitioning is given by way of example only. For example, in some embodiments, B. the SP circuit in the second implantable unit 154 containing only the ICS circuit in the first implantable unit 152 remains.

The advantage of in 1D shown wired system 150 is that a fully implantable system is provided in which one of the two implantable units, eg. B. the power unit 154 if necessary, can be exchanged in a small operation. As already indicated, the cable is 156 removable, this is the second unit 154 with the first unit 152 combines. The implantable connector that holds the cable 156 with the unit 154 connects, can be of any kind, z. B. of the The type conventionally used in implantable cardiac pacemakers, or the type shown in U.S. Patent No. 4,516,820 (Kuzma) or U.S. Patent No. 4,495,917 (Byers).

The external headboard 136 and the external control unit 138 as well as the programmer 108 can with the wired system embodiment 150 in the 1D is shown to be used in the same way as these components in the single unit embodiment 130 , in the 1C is shown used.

Referring to the 1E is a partitioned nutrition system 160 ("Proximity system"), which is similar to the one in 1D shown wired system 150 is that, however, no connection cable 156 used between the two units. As in 1E can be seen, has a first implantable unit 112 ' an ICS with an associated electrode assembly 114 on. An advantage of the nutrition system 116 is that the first implantable unit 112 ' essentially the same or identical to the ICS 112 which is used in existing cochlear stimulation systems (see 1A or 1B ). This allows for upgrading existing stimulation systems with an ICS 112 on a fully implantable system, as in 1E is shown. A second implantable unit 162 includes a speech processor (SP), circuitry, and a power source, e.g. B. a rechargeable battery. The second unit 162 is implanted so that it is in close proximity to the first unit 112 ' located. One related to the second unit 162 standing coil is with the in the ICS 112 ' aligned coil, as described in connection with the description of the 14A to 16 will be shown. This allows inductive coupling between the implantable units 112 ' and 162 in the same way as between the BTE unit 120 and the ICS 112 , shown in 1B , or between the headboard 106 and the ICS 112 , as in 1A is shown.

A suitable microphone, z. B. a "complete-in-cannel (CIC) microphone 134 of the type previously described is used to detect noise (pressure waves) and electrical signals corresponding to such sounds with the speech processor (SP) circuits in the implantable section 162 to pair.

The external headboard 136 and the external control unit 138 as well as the programmer 108 can with the partitioned nutritional system embodiment 160 , shown in 1E , are used in the same way as with the single-unit embodiment 130 , in the 1C and the partitioned wired system embodiment 150 , as in 1D is shown.

By using the in 1E The following advantages are achieved: (1) older implants, ie existing ICS units 112 , can be upgraded to fully implantable systems without affecting the implant unit 112 and the electrode 114 (2) implantable systems can be upgraded with improved battery technology (or other power source) and improved power-efficient SP circuits as they become available, in a minor operation for the patient: (3) batteries can (4) Charging, overriding, boosting, adjusting, and diagnosing can be done simply by having the implanted SP circuits through an external speech processor To get picked up.

improved Charging the battery

Next, the measures employed by the invention to make battery charging more efficient will be described. Such a description will, in general, be in connection with a single unit system 130 the in 1C shown, which is designed for use with a cochlear stimulator. It will be understood, however, that such measures are equally applicable to any other embodiments of the invention described herein.

Referring to the 2A It can be seen that the invention by an implant device 10 is embodied, which is a housing 12 , an internal battery 14 and an internal circuit 16 has been designed to improve the battery charging time and the life characteristics. The charging time of the battery is largely limited by the amount of heat generated during battery charging. During charging, a large amount of heat can be generated by the eddy currents, which are induced in the lead structures and current paths of the implant. If the temperature of the implant becomes too high, it may damage the surrounding tissue. The implant device in the present invention is designed to reduce the amount of heat generated during the battery charging time and that it extends the life of the battery.

As has already been pointed out, relates to a preferred application In the present invention, an implanted cochlear stimulation device. Therefore, in the following description is frequently referred taken on a cochlear implant device. It will, however emphasizes that the invention does not apply to a cochlear implant device limited is. The invention can be used with any implantable device be used, which reduces the eddy currents at a time Need to become, or when the implantable device is a magnetic Alternating flow is exposed, on the other hand generate eddy currents would.

Referring to the 2A There is an embodiment of the invention in a cochlear implant device 10 that, in addition to the housing 12 , a battery 14 , a circuit 16 and an implant lead 18 which extends from the housing comprises. The internal battery 14 and the signal processing circuit 16 are housed in the housing, and the housing is of a coil 22 surrounded, as in 2 B is shown. A large section of the interior of the case is from the battery 14 ingested. The housing is preferably implanted beneath the skin behind the ear of a patient, with the implant lead coiling into the cochlear space of the patient. The implant lead has electrodes 20 for stimulating the nerves within the cochlear with electrical pulses generated by the electronic circuit for audible noise signals from a microphone or the like, thereby enabling simulation of auditory perception. A typical implant lead has between 8 and 32 pairs of electrodes. Each electrode is connected to the circuit via a separate conductor.

The battery 14 is charged using a rectified AC power (or DC power that has been converted by other means from AC power, eg, efficient AC / DC converter circuits, also known as "inverter" circuits) from the coil 22 is taken, which is the case 12 surrounds. An outside unit 15 , which generates alternating magnetic fields, is applied to the outside of the patient's skin over the implant device 10 placed to charge the battery. The coil is powered by ceramic insulated pins with the electronic circuit 16 connected within the housing, which rectifies the alternating current, so as to generate a direct current, which is used to charge the battery with the power absorbed by the coil. However, the AC magnetic fields also induce heat generating eddy currents in the metal case (if metal), the electronic circuit and the electrode plates of the battery. Accordingly, the current consumption or charging current of the battery is limited by the maximum permissible housing temperature, ie the ability of the surrounding surrounding the implant living tissue to endure elevated temperatures. When charging the battery, increasing the case temperature by just a few degrees Celsius can be extremely dangerous and can damage the surrounding living tissue.

To reduce the heat in a metallic housing created by the induced eddy currents is the housing 12 made of a relatively inert biologically inert metal. Since the heat generated by the eddy currents is proportional to i ² R, where i corresponds to the current and R corresponds to the resistance, an increase in the resistance R of the metal housing reduces the amount of eddy currents and accordingly reduces the heat generated by the eddy currents. The thickness of the housing core or wall is also minimized as much as structurally possible to further increase the resistance in the housing core or wall. Preferably, the metal shell has a wall thickness of between 0.05 and 0.1 mm (0.02 and 0.004 inches) and is made of titanium ₆₄ (6% aluminum, 4% vanadium). Titan ₆₄ has a resistivity of 177 microohm * centimeter, which is about 60 times the copper resistivity.

Alternatively, the housing 12 be made of a different metal, such. As titanium ₈₁₁ (8% aluminum, 1% vanadium, 1% molybdenum) or Haines ₂₅ , or from a ceramic such. As aluminum oxide (AlO _x ) or zirconium oxide (ZiO _x ) with ceramic insulated through pins. However, a ceramic housing would require thicker walls, resulting in a larger implant device. Further, the housing may be made of a water-resistant plastic with an internal water absorber to absorb moisture that can slowly escape through the plastic housing.

The battery 14 is preferably a lithium ion battery or a nickel metal hydride (NiMH) battery. In an improved cochlear implant device 10 , which is exemplary of the present invention, consume the implant lead electrodes 20 about 1 milliwatt (mW) of battery power and the electronic signal processing circuitry 16 consumes about 6 mW of battery power. At such heights of power consumption, a 300 mW-hr battery will last for about 50 hours (or about 2 days). A typical rechargeable lithium-ion battery has a life of about 500 recharges, and if recharged every two days would have a life of about 3 years. As described below, more frequent battery charging can extend the life of the battery.

The heat generated by the eddy currents, which are induced on the electrode plates of the battery, is produced using plates 24 with elongated slots 26 reduced, which pass through a substantial portion of the plates, as in 3A is shown. Each electrode plate generally has a thickness of about 0.025 mm (0.001 inches), a width of about 25 mm (1 inch), and a length of about 25 mm (1 inch). The slots are normally cut using a saw blade having a thickness of about 0.025 mm (0.001 inch). In this way, after sawing, a gap of about 0.025 mm (0.001 inch) remains between the material of the plate, resulting in a comb pattern of conductive teeth 28 leads. The teeth may be formed to extend in only one direction or in different directions. The distance between the slots determines the width of the conductive teeth. In order to support higher magnetic fields associated with higher charging currents, the slots should be closely spaced, resulting in narrower teeth. While cutting more slots through the plate generally results in smaller induced eddy currents, each slot reduces the line capacitance of the plate and increases the manufacturing cost of the battery. An advantageous width for the conductive teeth is about 1 mm (0.04 inches), with the gap being about 0.05 mm (0.002 inches). The slot length may be shortened in the vicinity of a wire attachment point of the electrodes so as to increase the current capacity in the vicinity of the wire attachment point. Likewise, an insulating material can be introduced between the slots, such as. As nylon or polypropylene or other suitable insulating material. In addition, the electrode plates, although in 3 are shown as having a substantially square surface, having a variety of surface shapes and slot configuration, which are effective in reducing the eddy currents and filling the cavity of the housing.

The 3B and 3C make additional battery plates 24 which can be used with batteries of different shapes. Each one covered by slits 26 separate teeth 28 as previously described.

The 3D shows the way in which a small battery can be formed by the plates 24 of the 3B or 3C to be rolled. Regardless of the shape and form factor of the battery, the objective of the invention remains the same: the use of slots 26 in the plate 24 , which prevents the formation of closed current loops, since it is the closed current loops that lead to the formation of unwanted eddy currents.

As in 4 shown is the battery 14 composed of cells consisting of alternating layers of the first and second electrode plates 30 respectively. 32 consist. A first separator or separator 34 is made of polypropylene and has tiny holes or pores that allow water and salt, but prevent larger molecules and metals from passing through the separator. Further, the material of the first separator may seal the electrode plates. A second separator 36 completely isolates each battery cell or layer from the adjacent cells above or below the layer. A liquid paste of relatively high resistance is introduced between the electrodes and the separators. Since the paste has a relatively high resistance, the amount of heat generated by the eddy currents through the paste is very low.

The positive electrode is made of aluminum and the negative electrode Made of either silver or copper. Silver has a slightly better conductivity (+ 5%) as copper, but is generally more expensive than copper. If an electrode impregnated chemical compound matrix used, so can the chemical compound matrix on the leading teeth applied or coated thereon.

alternative can the conductive teeth long thin wires be impregnated by chemical threads repeatedly thwarted.

As in 5 shown is the entire metal housing 12 with a thin layer of Hysol Epoxide 38 coated with a thickness of about 0.025 mm (0.001 inch). The epoxy is a thermal insulator with a relatively low thermal conductivity compared to the thermal conductivity of the metal housing. In this way, the epoxy layer allows the metal case to heat from localized areas with relative high temperature in cooler areas of the housing passes before the heat can pass through the epoxy layer, which in turn prevents a significant increase in temperature of the adjacent living tissue. Accordingly, the epoxy coating allows faster recharging of the battery since the AC-induced heat generated at localized hot spots of the housing may spread, causing the surrounding living tissue adjacent to the localized hot spots to be exposed to lower local temperatures. In this way, an epoxy-coated metal housing remains below the maximum permissible housing temperature at higher charging currents.

As based on the 6 can be seen, is the circuit 16 on a circuit board 40 or a circuit board with circuit areas 42 and imaginary, nonconductive lines or boundaries 44 , The non-conductive lines prevent large circuit loops that would allow large eddy current loops in the circuit. The circuit is designed so that no components or conduction paths cross the non-conductive lines, thereby precluding the formation of large eddy currents in the circuit. In a multilayer circuit board, the imaginary, non-conductive lines should be 44 extend through all layers of the plate, or at least similar, non-conductive boundaries or lines 44 should determine the lay-out of each layer. Accordingly, the circuit layout is limited to the circuit areas, thereby preventing large eddy currents in the circuit layout and reducing the heat generated during battery charging to provide faster battery charging times.

In an alternative embodiment of the invention, as in 7 and 8th shown is the battery 14 ' from a tape with long electrodes 46 ' and 48 ' and separators 50 ' and 52 ' formed into a spiral (rolled) formed. In the spiral plane, the cross-sectional area of the thin electrodes is very small, with non-closed current loops being present in the longitudinal direction of each electrode, thereby inducing large eddy currents in the electrodes when charging through the coil 22 ' is prevented.

In a similar alternative embodiment of the invention shown in FIGS 9 and 10 shown is the battery 14 '' from four band components 54 formed, which are connected in parallel and wound into a spiral. Such a configuration advantageously allows a much shorter charging time than z. B. in the configuration of 7 the case is. The disadvantage of such a shorter charging time, however, is a smaller capacity, ie a lower battery current. The band components of an actual battery are much longer than those in the 6 and 7 . shown For clarity, the necessary separators are between the electrodes 56 and 58 not shown. The resistance along a single band may be significant with faster battery charging times or higher charging currents, and during these times considerable current flows through the band and may result in constant overcharge of the band of the battery near the terminals of the battery or permanent inadequate Charge the belts at the open end. Dividing the band into four shorter bands reduces a voltage difference along a single band by a factor of 4. Of course, more or less than four bands may be used in accordance with the present invention. The bands are parallel with each other via a middle ring 60 connected, which has a conductive outer surface 62 owns that from the conductive inner surface 64 is isolated. The first or the innermost battery electrode 56 is with the outer conductive surface 62 connected. The second or outermost battery electrode 56 ends behind the first electrode 58 and is folded at a right angle and wound around the middle ring so as to contact only the inner conductive surface.

The life of the rechargeable battery can be improved by having it only in areas 66 their work area is used with low voltage, as in 11 is shown. In particular, the life of the rechargeable battery is based on the number of complete discharges and charges or cycles affecting the battery 14 while maintaining its performance specifications. For a lithium-ion battery, a battery voltage of 2.5 volts means a fully discharged battery, and a battery voltage of 4.1 volts indicates a fully charged battery. However, completely draining or fully charging the battery "strains" the battery and limits its life, and operating the battery within a "low stress" area 66 of the working area of the battery can significantly extend the life of the battery. For example, the battery can be charged if its voltage drops to 3.0 volts (point 68 on the battery charge curve the 8th ) and charging to no more than 4 volts (dot 70 on the battery charging curve) that the battery is mainly operated in low-stress areas of their work area. If the battery even has sufficient capacity to operate for two days between recharge cycles, the battery life can be extended by recharging the battery daily or twice a day.

One coulomb may instead of, or in addition to, a voltmeter can alternatively be used to charge level to monitor the battery. The Coulomb counter can also show the power efficiency of the battery.

According to the invention, the circuit 16 ' on a long narrow strip 72 be designed from elastic material such. B. Kapion (trade name), as in 12 is shown. The circuit components 24 and the metallization traces 26 between the components are attached to the elastic strip. The elastic strip then becomes a C-shape or spiral shape in the housing 12 rolled, as in 13 is shown. As described above with regard to the spiral battery ( 7 ), prevents the C-shaped or spiral circuit 16 ' large current loops that could lead to large eddy current loops when charging the battery.

Fully implantable systems

Fully implantable systems according to the present invention have previously been described in connection with the 1C . 1D and 1E been described.

14A shows a plan view and 14B a side view of a kind of a partitioned, fully implantable nutrition system 160 ( 1E ). In the in the 14A and 14B the embodiment shown is the ICS 112 ' in the immediate vicinity of an implantable SP / PWR unit 162 , The ICS 112 ' is housed in a ceramic housing as described in US Pat. No. 4,991,582. A ceramic or equivalent material is preferably used as the housing material to facilitate the magnetic coupling through the housing. A metallic headboard 115 is hermetically sealed with one end of the ceramic housing. Electrical passages that are in the headboard 115 see, see a hermetic electrical connection of the individual conductors of the cable 116 (which to the electrode assembly 114 leads, but not in the 14A or 14B shown) with that in the ICS 112 ' accommodated electrical circuit.

The SP / PWR unit 162 is housed in a housing which is made of a metal, such as. Titanium, stainless steel, or a similar material that is compatible with body tissue, as previously described. Two electrical passages 176 pass through one side of the case and are attached to a coil 172 appropriate. The coil is connected to the coil in the ICS 112 ' is contained, aligned and arranged above it. The coil may be embedded in a suitable material, such as. B. an enveloping shape 174 made of silicone rubber or other suitable material and formed to be on the sides of the SP / PWR unit 162 and the ICS 112 ' adheres. A "complete-in-cannel" (CIC) microphone 134 enters the auditory canal adjacent to the implant site of the ICS 112 ' and the SP / PWR unit 162 placed. A "telecoil" connection couples magnetic energy into the microphone, which in turn uses it to power the internal circuits, and sound (pressure waves) detected by the microphone are converted to electrical signals that are transmitted through an RF Transmitter or other suitable connection over the short distance to the SP / PWR unit 162 be transmitted. If required, an external header can be used 136 (associated with an external programmer working in 14B not shown) via the implant devices on the outside of the patient's skin 110 be positioned so as to override the internal speech processor, provide a charging current or "boosting" current for the implant device, or perform fitting and / or diagnostic functions.

An alternate embodiment of the fully implantable, partitioned nutrition system 160 ( 1E ) is in the 15A and 15B shown. 15A is a plan view of such an embodiment and 15B is a page or profile view. As can be seen from these figures are the ICS 112 ' and the SP / PWR unit 162 placed laterally and close together. Each unit has approximately the same thickness. Electrical passages 176 ' at one end of the SP / PWR unit 162 see an electrical connection for the coil 172 ' in front. Preferably, the coil comprises 172 ' one or more windings of a suitable wire, e.g. A wire made of one of the precious metals and held together to form a cable or held within a suitable resilient cable channel.

When inserting the implant, the ICS 112 ' implanted in a conventional manner, and the SP / PWR unit is similarly implanted in close proximity thereto. The surgeon places the coil 172 ' such that they are the ICS 112 ' surrounds the cable over the enlarged portion of the cable with the electrode assembly 116 runs. The surgeon performing the implantation can use the coil, if necessary, sew at a suitable place. A microphone 134 and an external header 136 be with the SP / PWR unit 162 and the ICS 112 ' as described above.

Another embodiment of the fully implantable, partitioned nutritional system 160 ( 1E ) is in the 16 shown. As in 16 showing a profile view of such an embodiment is an ICS 112 ' and an SP / PWR unit 162 stacked. In the embodiment of the 16 it is preferred that the SP / PWR unit 162 also has a ceramic housing, similar to the ICS 112 ' , or on the other hand configured such that magnetic signals can thereby run without significant attenuation. An advantage of the embodiment of 16 is that with the SP / PWR unit 162 no hermetic passes must be used. It may rather have a sealed hermetic unit with its coil disposed within its housing. A disadvantage of the embodiment of 16 is that the combined stack of ICS 112 ' and SP / PWR unit 162 at least twice as thick as the laterally arranged embodiments, whereby a deeper pocket in the tissue of the patient must be formed at implantation, and which may possibly result in little bulging of the patient's skin at the site of implantation.

When implanting the embodiment of the 16 becomes the case of the SP / PWR unit 162 over the ICS 112 ' arranged so as to coil its coil with that of the ICS 112 ' align. If desired, a thin ferrite film 181 or a foil of another suitable low-resistance material coated with a suitable protective biocompatible material is inserted between the outer walls of the two units so as to apply the magnetic field associated with the inductive coupling to the narrow down and focus on the desired area.

Referring now to the 17 is a simplified functional block diagram of one embodiment of a nutritional system 160 ( 1E ). It is emphasized that the in 17 The configuration shown is functional, and is not meant to be limiting. It is noted that those skilled in the art can easily design a circuit that meets the requirements of the art 17 (as well as the 18 ), provided that the teachings described herein are known to him.

As in 17 can be seen is the ICS 112 ' at the electrode assembly 114 attached and also includes two coils 180 and 182 , The sink 180 receives a carrier signal, and this is rectified using the diodes CR1 and CR2, and this rectified signal then provides the operating power to the ICS. The sink 182 receives a modulated signal, wherein the modulation includes the data that determines and controls the stimulation signals applied to the individual electrodes of the electrode assembly.

The SP / PWR unit 162 includes a rechargeable battery 192 which is designed to operate at a nominal operating voltage of 1 to 2 volts. Such a battery 192 Provides the operating power for the analog front (FE) circuit 188 , the digital signal processing (DSP) and the control circuit 184 and a "powerdriver" circuit 190 ready. The "powerdriver" circuit 190 generates the carrier signal, inductively or magnetically in the ICS 112 ' over the coils 194 and 180 is coupled. The analog FE circuit 180 receives signals from the microphone 134 over the coil 186 , temporarily amplifies and edits these signals for the DSP / control circuit 184 , The DSP / control circuit 184 applies a selected speech processing strategy to the detected signals, generates appropriate pacing control signals for the ICS, and transmits these control signals to the ICS 112 ' about the magnetic connection coming from the coils 196 and 182 is produced. The CR3 diode allows the power passing through the coil 194 from an external headboard 136 (eg when recharging) is received, which is the voltage of the voltage 192 exceeds the battery 192 charging.

When using a nutritional system of in 17 The type shown is the average battery life, which is available when such a system with an ICS 112 ' coupled as disclosed in the '726 patent, or an equivalent system, assuming the indicated charging time per day and battery type indicated, as shown in Table 1.

TABLE 1 Estimated Battery Life

A NiMH battery, or a nickel metal hydride battery, a proven reliable battery for implantation purposes, is used to arrive at the information shown in Table 1. In Table 1, "CIS" means "Continuous Interleaved Sampler "strategy, and this stands for a special kind of language editing strategy that only stimulate a pair of electrodes at a given time. on the other hand means "SAS" for a "Simultaneous Analog Stimulation "strategy, which is a kind of language editing strategy which simultaneously stimulate several pairs of electrodes simultaneously. As shown in Table 1, an ICS operation consumes along with a SAS strategy more power and requires longer recharge times per day, as opposed to an ICS operation along with a CIS strategy the case is.

18 FIG. 12 illustrates a functional block diagram of the main circuits used in a wired system embodiment of the invention. FIG.

For the most part, the block diagram includes the 18 Circuits that perform the same functions as those associated with 17 have been described. The main difference between the circuits of the wired system 18 and the circuits of the nutrition system of the 17 is that the wired system is a cable 156 used to the ICS 112 ' with an SP / PWR unit 154 ' electrically connect. This in 18 The cable shown comprises only two conductors and is coupled at each end by means of carriers. The sink 197 located in the hermetic sealed dwelling of the SP / PWR unit 154 ' is coupled via carrier with a coil located at the left end (as in 18 ) of the cable 156 located. Similarly, the coil 181 located in the hermetically sealed dwelling of the ICS 112 ' is contained, coupled via carriers with a winding, located at the right end of the cable 156 located. The conductors, with the coils on the left and right ends of the cable 156 are connected, pass through suitable through-conductors of their respective housing, so that the cable itself is not hermetically sealed. At some point at the ends or along the length of the cable 156 a suitable connector is used which allows the cable to be detachably connected between the two implantable units. Such a configuration prevents such a DC over the connection between the SP / PWR unit 154 ' and the ICS 112 ' flows, which in turn is desirable. Preferably, power is transmitted through the cable 156 as an AC carrier signal and data are transmitted as modulation of the AC carrier signal.

It should be noted that other variations of the connection cable 156 can also be used as previously described. For example, the connector may have five or six conductor cables that allow transmission of the data between the two packages on two or three wires (conductors) while transmitting power on the three wires (conductors) via a capacitively coupled three-phase square wave signal. In such a case, where a capacitive coupling is used at each end of the cable, a transmitter coupling is not required. Such a capacitively coupled cable prevents the flow of DC outside the hermetic seal of the packages, as desired. The three-phase power signal, when received at the other package, is recombined to produce a DC signal with negligible ripples using a synchronized circuit without the need for use of filter capacitors.

A preferred three-phase transfer system for transferring power between two implant devices, such as an implant device. B. the SP-PWR unit 154 ' and the ICS 112 ' is in the 19 and 20 shown. The 19 is a functional block diagram of such a three-phase transmission system, and the 20 is a waveform diagram illustrating the operation of the circuit of the 19 represents. Like from the 19 you can see that is the battery 14 connected to the three switches S1, S2 and S3. (It should be noted that in practice such switches are normally solid state switching devices, as is known in the art, while these switches are shown as mechanical switches comprising two terminals and an armature between the two Connections or in a ground-free position is switched). Each switch can take a "+" position, a "0" (or OFF) position and a "-" position, in the "+" position is the armature of the switch with the positive side of the battery 14 connected. In the "-" position is the armature of the switch with the negative side of the battery 14 connected. In the "0" position the switch is not with the battery 14 connected, he is open. The armature of each switch is connected to a coupling capacitor C and then to an electrical continuity pin or connector 202 which makes it possible to make an electrical connection from within the hermetically sealed housing to the three conductors P1, P2 and P3 so as to form part of the (P / O) cable 156 outside the hermetically sealed housing, and the two implant devices of the wired system 150 connects ( 1D ).

In use, the switches are controlled using a conventional timer circuit (not shown) which connects one or both armatures to one side of the battery at the time the other armature is connected to the other side of the battery. During a phase transition, that is, when an armature switches from one polarity of the battery to the other, the switch enters its "0" state so as to create a dead time if the armature is de-energized This avoids the introduction of inrush voltages to the armature Anchor lines, which in turn creates a clean DC voltage when the P1, P2 and P3 phases at the other end of the cable 156 be recombined in the other implant device. The advantage of this approach is that it avoids the use of large filter capacitors which, on the other hand, must be used in conventional rectifier circuits. For a small volume implant device, it is highly desirable not to have to use large filter capacitors.

To illustrate the switching process is with respect to the 20 which represents the voltage waveforms at the three phase conductors P1, P2 and P3. As in 20 is visible at time T1, z. B. P1 is connected to the "+" side of the battery, P2 is connected to the "-" side of the battery, and P3 is connected to the "+" side of the battery At time T1, a timer circuit detects 204 which controls the operation of the three switches S1, S2 and S3, that the switch S3 (connected to the conductor P3) must go to the "-" side of the battery, so a short time after the time T1, the switch S3 is in the " 0 "state in which he remains at time T2. This means that the voltage at P3 goes back to zero and stays there until some time after time T2 the switch S3 is switched to the "-" side of the battery. - Connected to the side of the battery, which provides a clean DC voltage signal across the other end of the cable through the P1 and P2 conductors At time T3, switch S3 has completed its switching cycle and is immovable with the "-" side of the battery 14 as well as switch S2, which in turn means that at time T3 both P2 and P3 provide a "-" signal while P1 provides a "+" signal. However, at time T3, the timer circuit detects 204 in that the switch S2 (connected to the conductor P2) must begin its transition to the "-" side, so shortly after the time T3 the switch S2 has switched to the "0" state, where it remains at the time T4. This means that the voltage at P2 goes back to zero and stays there until the switch S2 switches over to the "+" side of the battery some time after time T4, this process or cycle continues as long as the three switches S1, S2 or S3 change their states between "+" and "-", passing through their "0" state.

At the receiving end of the cable 156 within the other implant device, e.g. Within the ICS 112 ' For example, a similar switching circuit is used to recombine the signals to provide a desired DC voltage for driving the circuitry found in the receiving implant device. To properly recombine the P1, P2, and P3 signals, appropriate synchronization with the timer circuits in the first implant device is needed (ie, the timer circuits used to generate the three-phase signals in the P1, P2, and P3 conductors). , During such synchronization directly from the timer circuit 204 on a fourth conductor in the cable 156 is included, however, it is preferable to use the synchronization information from the P1, P2 or P3 signals themselves, whereby no extra conductor in the cable 156 must be present. At the receiving end of the cable 156 it is known which conductor belongs to which phase, and the order or sequence of the switching phases is also known. By the P1 signal at the receiving end z. B. is monitored, it is possible to detect when the transition between the "+" and "-" state takes place. This transition, once it has been detected, can subsequently be done can be used to trigger a suitable synchronization circuit in the receiving implant device, so as to reliably reproduce the necessary timing signals to recombine the three-phase signals P1, P2 and P3.

Even though the present invention in terms of a cochlear implant device has been described, and while certain features of the invention particularly for use in one cochlear implant device are suitable, however, it is emphasized that the features of the invention associated with the reduced eddy currents as well as the complete implantable partitioning (for example, partitioning different Functions in separate coupled implanted packages) in others implantable neural or muscular stimulation devices or other implantable devices.

While the Invention described herein by way of specific embodiments and applications thereof are numerous Modifications and variations for the skilled person conceivable, without the scope of the invention, as in the claims is destined to leave.

Claims (16)

Implant system ( 160 ), comprising two housings, namely a first housing ( 112 ' ) and a second housing ( 162 ); an electrical circuit ( 16 ), which provides a desired stimulus / test function; a charging agent ( 22 ) for receiving electrical energy induced by external AC magnetic fields; and a rechargeable energy source ( 14 ) coupled to the charging means and the electrical circuit; the electrical circuit ( 16 ) in the first housing ( 112 ' ) and the charging means ( 22 ) and the energy source ( 14 ) in the second housing ( 162 ), and wherein the implant system is characterized by: means for electrically coupling the first and second housings having an inductive coupling comprising a first coil associated with the first housing and a second coil associated with the second housing; first and second coils are aligned with each other to allow the coupling of AC signals therebetween. The implant system of claim 1, wherein the rechargeable energy source is a rechargeable battery including first and second electrode plates ( 24 ), which are designed to reduce the amount of eddy currents induced in the battery electrodes by the external AC magnetic fields during battery charging. An implant system according to claim 2, wherein each battery electrode is relatively flat and has a plurality of slots ( 26 ) extending over a substantial portion of the electrode so as to produce regions of the electrode each having a relatively long, slender shape. Implant system according to claim 2 or 3, wherein the first and the second electrode have long thin electrodes, the are wound into a spiral. The implant system of claim 4, wherein the wound first and second electrode to a relatively flat, pancake-like Form are formed, which occupies more than 50% of the internal volume of the housing. An implant system according to claim 2, wherein the charging means comprises a coil ( 22 ), which within the housing ( 12 ), and further comprising an external energy source ( 15 ) for coupling the operating energy into the coil ( 22 ) so as to provide operating power to the electrical circuit ( 16 ) so that the battery ( 14 ) provided operating energy supplements. An implant system according to claim 2, wherein the charging means comprises a coil ( 22 ) within the housing ( 12 ), and further comprising an external energy source ( 15 ) for coupling operating energy into the coil ( 22 ) so as to provide operating power to the electrical circuit ( 16 ), which are supplied by the battery ( 14 ) provided operating energy replaced. The implant system of claim 2, wherein the rechargeable Battery has a NiMH battery. The implant system of claim 1, wherein the first coil is within the first housing and the second coil is external to the second housing but electrically connected to the circuit within the second housing is connected. The implant system of claim 1, wherein the second coil is in a material ( 174 ) which holds the coil against an outer surface of the first housing. The implant system of claim 1, wherein the second Coil around the first housing is winding. The implant system of claim 1, wherein the first Coil inside the first housing and the second coil itself within the second housing and the first and second housings are each relatively flat stacked housing exhibit. The implant system of claim 1, wherein the coupling agent a detachable cable, which forms the circuit inside the first housing with the electrical circuit within the second housing electrically combines. The implant system of claim 13, wherein the cable at both ends with the circuits in the first and the second Housing transfer coupled is. The implant system of claim 13, wherein the cable at both ends with the circuits in the first and the second casing capacitively coupled. The implant system of claim 15, wherein the capacitive coupled cable comprises at least three conductors, and wherein a three-phase switching circuit in each of the first and second housings is used to power from the power source in the second housing to the circuit in the first housing transferred to.